Changes

Remove speech codec list from bearer_cap for phase 1 mobile station

According to TS 04.08 Clause 10.5.4.5.1, the octet 3a ect. shall not be
included, if only GSM full/half rate speech version 1 is supported.

As phase 1 mobile stations only support FR and HR speech, the speech
list in the bearer capability must be reduced to the codecs listed
above.

The octet 3a ect. must be omitted when encoding bearer capability for
phase 1 mobile stations. This is done by removing the speech list.

I do not use a "codec filter", because it is not required. The phase 1
mobile station can only respond with codecs it supports, so no filtering
is required.

Related: OS#6461
Change-Id: Idd267dad0ade18cee7d5be813a57e1ee3168e2db